1. Field of the Invention
The present invention relates to a machine for picking up and storing tie plates of a railroad track comprising ties and two rails supported thereon.
2. Description of the Prior Art
In track rehabilation operations requiring the removal of individual damaged ties and their replacement by new ties, the tie plates interposed between the damaged ties and the rails are collected after removal of the spikes fastening the rails to the ties, and the collected tie plates are then used again when the rails are fastened to the replaced ties. It has long been the practice to remove the tie plates manually from the damaged ties after the rails were slightly lifted by winches. This was not only very time-consuming but often led to accidents because of the tensional stresses on the lifted rails and the unsteady support of the winches on the loose ballast bed.
In our U.S. Pat. No. 4,862,806, dated Sept. 5, 1989, we disclosed a mobile tie gang apparatus and tie exchange method wherein groups of ties are sequentially exchanged in an existing railroad track. The apparatus comprises a continuously moving train of elongated, bridge-like machine frames mounted on undercarriages, and a succession of different individual devices are longitudinally displaceably mounted in upwardly recessed portions of the machine frames and are operative to effectuate different sequential operations for exchanging selected old ties for the new ties. While in operation during the continuous advancement of the train, the devices are held in place. These devices include a spike puller carried by the leading machine frame, a magnetic drum for continuously collecting the pulled spikes, and a tie puller for partially pulling the selected ties out of the track. Mounted on the following machine frame is a longitudinally displaceable magnetic tie plate pick-up device to remove the tie plates from the partially pulled ties which are then fully pulled out of the track by a tie pulling and inserting device.
Instead of the tie plate pick-up device disclosed in this patent, magnetic tie plate pick-up devices which are vertically adjustable between a lower pick-up position and an upper tie plate depositing position, wherein the pick-up magnet is briefly demagnetized to deposit the picked-up tie plate on a storing device, have been used.
Tie gang trains of this type have been operated with great success but their use is economical only if large numbers of ties are to be exchanged.
Vertically and transversely adjustable tie exchange devices for pulling and inserting ties are well known and have been disclosed, for example, in U.S. Pat. No. 4,611,541, dated Sept. 16, 1986.